Abstract Due to the excellent pharmacological effects of polysaccharides, scholars have attached importance to researches on them. However, the high-value utilization and development of polysaccharides have been greatly limited by the high molecular weight, poor solubility and bioavailability. The degraded polysaccharides have stronger biological activities than those before degradation, such as antioxidant, anti-tumor, immune-regulatory, anti-hyperlipidemia, anti-inflammatory, regulating intestinal microbe and so on. At present, many effective methods have been applied to prepare low molecular weight polysaccharides, like chemical degradation, physical degradation and biodegradation methods.
Keywords Polysaccharides; degradation; biological activity.